In an effort to keep the Zika virus out of the nation’s blood supply, many U.S. blood banks, including BloodSource in Sacramento, are imposing a 28-day blood donation waiting period for people who have traveled to countries where the disease has spread.
As of Wednesday, Sacramento blood donors who have visited Mexico, the Cape Verde Islands, the Caribbean, Central or South America, or Samoa are being asked not to donate blood for four weeks after leaving those countries.
The blood banks are following a voluntary protocol issued by AABB, formerly the American Association of Blood Banks, which is the professional body for U.S. blood donation agencies.
The Zika virus outbreak began last May in Brazil and has been declared a global public health emergency by the World Health Organization. Though only 1 in 5 people who contract the virus from a carrier mosquito become sick, researchers suspect it’s causing a severe neurological condition called microcephaly in babies of infected pregnant mothers. About 4,000 babies have been born with the defect, characterized by a small head and incomplete brain development, since the outbreak began.
Brazilian health officials recently confirmed that two cases of Zika virus were transmitted through blood transfusions.
A person stays infected with Zika for an average of seven to 10 days, said Dr. Chris Gresens, senior medical director and vice president of global medicine for BloodSource, a network of 15 blood banks throughout Northern California. If an infected person gives blood during that window, he or she could introduce the virus to the blood supply, and the virus could be passed on to a blood transfusion recipient.
Gresens said there’s no efficient and affordable way to screen blood for Zika.
When asked about the possibility of transmitting the virus through blood, he responded: “How often it’s going to occur is anybody’s guess. We’re catching this problem early, but we’ll see what happens in the coming months.”
Even before AABB announced its recommendation, scientists at BloodSource were discussing how to implement their own 28-day deferral for donation centers, Gresens said. After the protocols were released, BloodSource began printing Zika signage and training its staff to take careful note of travel histories.
The U.S. Food and Drug Administration is working on its own deferral guidelines for blood banks but is supporting the AABB recommendation for now, said an FDA spokesperson in an email. Other countries including Canada and the United Kingdom have taken steps to protect their blood supplies, with some recommending a 21-day waiting period.
The four-week deferral should lower the possibility of transmitting Zika virus through a blood transfusion, Gresens said.
“As you can imagine, when deciding how long to prevent a donor who may have had a recent infection from donating, we want to have a good cushion interval,” he said. “We don’t want to take any risks with an outlier who has an especially long infection.”
The blood bank also has protocols in place to retrieve donated blood if a donor realizes after giving blood that their recent travel history puts them at risk for Zika. People should not donate blood if they’re experiencing headaches, joint pain, fever, rash or pinkeye.
The deferral may cause a dip in the number of people donating blood in Sacramento, Gresens said.
Since 2015 there have been 35 cases of Zika brought to the U.S. by people who recently traveled to regions where the virus is prevalent, including one confirmed in Yolo County on Wednesday. There has been no local transmission of Zika virus within the U.S.
BloodSource is asking anyone who has not traveled to Zika-affected countries lately and meets other donation eligibility requirements to give blood this winter to make up for the anticipated 2 percent drop in supply.
“We value our donors from everywhere, but how many of those individuals won’t be available to give will be an issue of importance to us,” Gresens said.
Dr. Steven Kleinman, senior medical adviser to AABB, said he doesn’t expect to see a blood availability problem following the deferral.
“We can recruit other donors to replace those donors,” Kleinman said. “We think we’ll have enough blood on the shelf for people who need transfusions, even with the deferral in place.”
Samuel Gregg, a midtown resident who donates at BloodSource regularly, said he was happy to hear about the waiting period when he went to the midtown center on Wednesday.
“It’s good to see that they’re doing something to mitigate the risk,” he said.